The camellia genus contains a number of flowering shrubs and trees native to China and Japan. Camellias are characterized by their showy, rose-like flowers, which may be in colors ranging from hot pink to white or red. Like all plants, camellias are susceptible to insect infestations, which may cause mild or serious damage if not treated swiftly.
Camellia plants are susceptible to insects such as scale insects, gall mites and black vine weevils. Scale insects have a bumpy, rough appearance and may be brown, white or reddish orange. Cottony cushion scale insects have a puffy, cotton-like appearance due to the insect's inflated egg sac. Gall mites are tiny yellow or orange insects that appear in dense masses on the undersides of leaves. Black vine weevils are large black beetles that have a scaly, dimpled appearance. Full-grown weevils can be found chewing on leaves, while rice-shaped whitish larvae can be found in the soil attacking roots.
Scale insects suck the sap out of leaves and branches. In severe infestations, leaves may curl up and drop prematurely. The insect also secretes a sticky substance that attracts ants and causes an unsightly black mold. Gall mites cause unattractive raised green or brown blisters on camellia leaves. Black vine weevils attack foliage, causing jagged notches and tears on leaves and flowers. The larvae may harm the plant's roots, making it more susceptible to disease.
Scale insects such as cottony cushion scale insects and cottony camellia scale insects are best treated with biological predators such as the vedalia beetle, which will aggressively prey upon scale insects. Gall mites are difficult to remove. Pruning away infested leaves may be your best chance at uprooting a gall mite colony. Adult black vine weevils can be removed with a timed insecticide. Larvae are best removed by releasing parasitic nematodes, tiny insects that will feed on the larvae but not the roots.
Your best defense against camellia insect damage is to take good care of your camellia plant. Healthy, strong shrubs are less likely to attract harmful insects. Be sure to follow the proper care requirements for your camellia species. In general, camellias prefer an acidic, rich soil that's well-draining and moist. The shrubs are best suited to humid, temperate environments that get either full or partial sunlight. You can apply a horticultural oil spray after the plant flowers in spring to help prevent scale insect infestations.
It is always safer to use natural methods when treating a pest infestation. Insecticides and pesticides contain harsh chemicals and should be used as a last resort when other control attempts have failed. Always follow instructions exactly and save the original container for access to dose and emergency information. Never pour insecticides down the sink or into storm drains, as they can pollute waterways.